Communication networks have become necessary adjuncts in conducting business on a national and global scale. The existing voice and data networks provide fast and convenient facilities for people and machines to communicate with each other over long distances without the inconvenience of traveling in order to conduct business. These networks, in many instances, are also more reliable and more economical than other forms of communication.
While current networks provide adequate facilities for point-to-point communication, it is desirable to enhance these networks for multi-point operation whereby many customers can participate in conferences to exchange information by voice and other means.
An example of this might be an audio/video conference involving several remotely located business associates, each having a video terminal. In addition to the video terminal, some conferees may have other types of data terminals, such as graphics units, electronic chalk boards, high-speed printers, etc., all of which can be used for communicating information over the network that may be presented at the terminal in different forms. For convenience, these, and other forms of communication, will be referred to herein by the generic term "data" communication; and it is not intended that they be limited only to those forms mentioned above.
The conferencing of data terminals can be achieved through dedicated, or so-called, private line networks. These networks are generally custom-designed so that all terminals are compatible with respect to their features and capabilities. Thus, any terminal in the network can "talk", i.e., exchange data, with all other terminals in the network.
While the above dedicated networks are suitable for their intended purpose, they have certain limitations in that all data terminals must be compatible with respect to features and capabilities. This limitation becomes even more burdensome when the network is shared by many customers, and each customer is allowed full access to all other customers.